Flow device



Sept. 23, 1941.

C. S. CRICKMER ET AL FLOW DEV I CE Filed Oct. 17,

5 Sheets-Sheet l Char/es 5. Crick/fie! dob)? 6/ Lane Sept. 23 1941.

FLOW DEVICE Filed Oct. 17 1958 C. S. CRICKMER ET AL 3 Sheets-Sheet 2 C bar/es .5. Crick/nefdo/m cl Lame Sept. 23, 1941. cjs. CRICKMER ET AL 2,256,704

FLOW DEVICE Filed Oct. 17, 1938 s Sheets-Sheet 5 Patented Sept. 23, 1941 FLOW DEVICE Charles S. Crickmer and John J. Lane, Dallas, Tex., assignors to Merla Tool Company, Dallas,

Tex., a firm of Texas Application October 17, 1938, Serial No. 235,470

18 Claims.

This invention relates to new and useful improvements in flow devices.

One object of the invention is to provide an improved device for controlling the admission of a lifting fluid, such as gas or air, into a liquid column whereby the column is aerated and the liquid raised or lifted, the device being particularly adapted for use in oil wells to lift the well liquids to the surface.

An important object of the invention is to provide an improved well flow device having a single valve element which is actuated by a predetermined pressure diiferential between the liquid and the lifting gas and which is so constructed that the valve element admits a charge of gas and then completely shuts off, whereby the device is particularly adapted for use as an intermitter to admit an auxiliary lifting fluid to a liquid column in a well having a relatively low standing liquid level.

An important object of the invention is to provide an improved well flow device having a movable valve element actuated by the pressure diiferential across said element, the valve element including a gradually reduced or tapered pin which is movable axially of the gas inlet opening, whereby as the element moves toward a closed position, the pin enters the inlet opening to cause said pin to act with a piston effect since a greater pin area is, in eifect, exposed to the pressure moving the valve element to a closed position, as said pin enters the inlet; such piston effect assuring the positive shutting or closing of the inlet after the charge of gas has been admitted.

Another object of the invention is to provide an improved flow device, of the character described, wherein a single valve plunger has its upper end exposed to the liquid pressure in a well tubing and its lower end exposed to the gas in the well casing, together with resilient means for urging the plunger downwardly against the gas pressure; the plunger also having a pin provided with a curved, tapering surface at its upper end, which pin is movable relative to the gas inlet opening leading to the tubing, the curvature of the pin, together with the force of the resilient means, controlling the pressure differential necessary to operate the valve plunger.

A further object of the invention is to provide an improved device, of the character described, having a valve element which is arranged so that the incoming gas is shut off just prior to the closing of the gas admitting opening leading to the liquid column, whereby the pressure created by the incoming gas surrounding the valve element is reduced to permit said element to be rapidly seated, thereby assuring positive seating of the valve element.

Still another object of the invention is to provide an improved flow device which is simple in construction and operation and which incorporates only a single moving part, the device being applicable to various well conditions and capable of use either as an intermitter or as an ordinary flow valve; the construction of the valve element controlling to some extent the pressure differential necessary to operate the valve.

A construction designed to carry out the invention will be hereinafter described, together with other features of the invention.

The invention will be more readily understood from a reading of the following specification and by reference to the accompanying drawings, in which an example of the invention is shown, and wherein:

Figure 1 is a View, partly in elevation and partly in section, of an improved flow device, constructed in accordance with the invention, and showing the same mounted on the outer side of a tubing string,

Figure 2 is an enlarged transverse, vertical, sectional view of the device, with the valve ele- -ment in an intermediate or open position,

stantially a right angle, to Figure 5 with the valve element in its uppermost position,

Figure 7 is a horizontal, cross-sectional view taken on the line 'l'l of Figure 5,

Figure 8 is a horizontal, cross-sectional view taken on the line 88 of Figure 5,

Figure 9 is a View similar to Figure 2, showing another form of valve element,

Figure 10 is a horizontal, cross-sectional view taken on the line li!!0 of Figure 9,

Figure 11 is a transverse, vertical, sectional view of a modified form of flow device,

Figure 12 is a horizontal, cross-sectional view taken on the line l2l2 of Figure 11,

Figure 13 is an elevation of a modified form of metering pin which may be mounted on the upper end of the valve element, and

Figure 14 is a' view similar to Figure 13 showing still another form of pin. 7

In the drawings, the numeral l designatesthe well casing of an oil well and the usual well tubing H extends axially therethrough. The lower end. (not shown) of the casing is open and the well liquid from the producing area enters said casing and rises to a level therein, which level varies with the'particular conditions of the well. The lower end of the well tubing extends below the normal standing liquid level, whereby the well liquid rises upwardly in the tubing. A well packer [2, of any suitable construction, is mounted in the tubing string near the lower end thereof and packs off the annular space between the casing and tubing in the usual manner, whereby the well liquid entering the lower end of the casing cannot rise in said casing but must flow upwardly in the tubing; A flow device A, constructed in accordance with the invention, is connected in the tubing string above the packer and is in a plane below the normal liquid level standing in the tubing. As' will be explained, a lifting medium, such as gas or air, is introduced into the casing ll], flowing downwardly therethrough, and the flow device A controls the admittance of this lifting medium int the liquid column standingin the well tubing.

The device A is particularly adapted to intermittently admit gas, as needed, to the liquid column to raise the same to the surface and may be termed an intermitter. The conditions of the well may be such that a period of time is required for the well liquid to build up to a normal standing level in the tubing and the device A is arranged to be actuated by the differential'in pressures between the gas in the casing l0 and the liquid in thetubing, as will be hereinafterexplained, whereby a predetermined liquid level'is necessary before gas is admitted to the-liquid column to raise the same. After the liquid column is'raised, the device A automatically shuts off the gas flowing into the tubing through said device and the liquid level must again build up in said tubing before :gas is again admitted thereto.

. Since the device is adapted to be connected in the upper end of the cylinder is externally screwthreaded and is screwed into the threaded bore l 6 of the upper boss [5. When so connected, the top of the cylinder is substantially flush with the bottom of the radial port !8. The extreme lower end of the cylinder is internally screw-threaded and receives a cap or plug 22 which has an axial bore 23 extending therethrough. The outer diameter of the plug and cylinder is such that when the upper end of the cylinder is connected within the boss [5, the lower end of the cylinder and plug snugly engage the wall of the recess in the lower boss. As clearly shown in Figure l, the bottom of the plug 22 is spaced from the bottom of the recess 20 whereby a space is provided therebetween. Such space permits an unrestricted flow of gas from the casing to pass through the axial bore 23 of the plug 22 and enter I4 which has its upper and lower ends externally i screw-threaded, whereby the sleeve may be readily connected in the tubing string I l by means of coupling collars I I. A radially extending boss 15 is welded, or otherwise secured, to the upper end of thesleeve at one side thereof and said bass has an internally screw-threaded bore at its lower end. A recess or chamber I1 is formed within the boss above the bore l6 and this chamber communicates, through a radial port 18, with the interior of the sleeve I4 and, therefore, with the interior of the well tubing II. An elongate boss l9, having substantially the same radial projection as the upper boss I5, is secured to'the lower end of the sleeve I 4 and is in vertical alinement with said upper boss. The upper portion of the boss 9 is formed with a substantially semicircular recess 20, as is clearly shown in Figthe interior of the cylinder 2!. It is noted that the lower boss braces and supports the lower end of the cylinder 2!, which cylinder could be made of one piece; however, for purposes of assembly and disassembly, it is preferable that said cylinder be constructed in two sections.

The lower section of the cylinder 2| is provided with an axial bore 24 which has its upper portion reduced at 25 whereby an internal annular shoulder 26 is formed within the cylinder at substantially mid-height thereof. The axial bore 21 of the upper section 2| a of the cylinder has its lower portion gradually enlarged, whereby an enlarged chamber 28 is provided immediately above section Zlb, An internal annular seat or shoulder 29 is located at the intersection of the chamber 28 and the upper portion of the bore 21.

An elongate plunger or piston 30 has a sliding fit within the reduced portion 25 of the cylinder bore and its lower end projects into the lower portion 24 of said bore. The extreme lower end of the plunger has an enlarged, conical head 3|, preferably integral therewith and the head is arranged to engage an annular bevelled seat'32,

which is formed on the upper end of the plug 22 and which surrounds the axial bore 23 thereof. This head serves as a check valve to prevent back flow. A coiled spring 33 surrounds the lower portion of the plunger, being confined between the head 3| and the internal shoulder 26 with the bore, and said spring exerts its pressure to constantly urge the plunger downwardly so as to urge the head toward its seat.

The upper end of the plunger has an upstanding axial pin 34, preferably made integral therewith, and this pin is an important feature of the invention. The contour or shape of this pin is subject to variation, as will be explained, but as shown in Figures 1 to 3, said pin is substantially cylindrical in cross-section. The lower portion a of the pin has a constant diameter, while the upper portion is curved or tapered inwardly, the diameter graduallyreducing to an axial point or extremity. The base of the pin has an outer diameter less than the diameter of the plunger 30,

whereby an external. annular shoulder 35 is prochamber 28' through the bore 21 is completely shut off.

Below the external shoulder 35 at the base o th pin 34, the plunger 30 is formed with a plurality of vertically disposed grooves or flutes 36- which are spaced around the upper portion. of

the plunger. The upper ends of the flutes terminate short of the shoulder 35, whereby a portion 35a of the outer surface of the plunger is disposed between the flutes and the shoulder. When the plunger is in its lowermost position (Figure 1) with the conical head 3| resting on the seat 32, the upper ends of the grooves or flutes are below the top of the section 2lb of the cylinder 2|, while the lower ends of the plunger are just above the internal shoulder 26 within the cylinder bore, whereby the grooves are located entirely within the reduced portion 25 of the cylinder bore.

Radial gas inlet ports 31 are drilled through the wall of the cylinder and have their inner ends communicating with the upper end of the reduced portion 25 of said bore. Since these ports extend entirely through the cylinder wall, it is manifest that the lifting gas within the casing I may pass through said ports into the bore of the cylinder. The location of the ports is such that they communicate with the vertical grooves or flutes 361 in the plunger when the plunger is in a lowered position and, therefore, the lifting gas may enter said grooves. However, the length of the grooves is less than the length of the reduced portion 25 of the cylinder bore and, therefore, the gas which enters said grooves when the plunger is in its lowermost position cannot escape from the ends of said grooves and is trapped therein.

However, when the plunger moves upwardly, the upper ends of the grooves move out of the portion 25 of the bore and enter the enlarged chamber 28. This uncovers the ends 'of the grooves and the gas may then flow from the grooves into the chamber 28 and then upwardly through the bore 21, chamber 11, port 18 and into the tubing string. It is pointed out that the spacing of the upper ends of the grooves from the shoulder 35 is important for by varying this spacing the area of the surface 35a is increased or decreased. If increased, the plunger must move a greater distance before the grooves communicate with the chamber and, therefore, a greater pressure must be built up in the grooves before the lifting gas is admitted.

The lifting gas is thus admitted to the tubing from the casing and continues to flow into the tubing until the plunger has moved upwardly a suflicient distance to move the lower ends of the grooves or channels upwardly past the inlet ports 31. As soon as this occurs, further flow of lifting gas from the casing is shut off. It is noted that the length of the channels is less than the distance which the plunger must move in order to engage the shoulder 35 with the seat 29 and, therefore, the lower ends of the grooves or channels move upwardly past the inlet ports 31 before the shoulder 35 engages the seat 29 to completely close the bore 21. With such arrangement, the upward movement is not completed when the incoming gas from the casing is shut oiT, with the result that the bore 21 remains open a short time after the gas inlet ports 31 are closed and, thus, the chamber 28 may be emptied before upward movement of the plunger is halted.

In operation, when the device is lowered into the well casing with no gas pressure in said casing, the plunger 30 is in its lowermost position, as shown in Figure 1, being held so by the coiled spring 33. After the device has been positioned at the proper elevation and the well tubing is set, the auxiliary lifting fluid, such as gas or air, is introduced into the upper end of the well casing l0 and flows downwardly through the annular space between said casing and the well tubing. For purposes of this description, it will be assumed that the lifting medium is gas and said gas is built up to a desiredpressure, depending on the particular well. The gas pressure within the casing acts against the lower end of the plunger 30 through the bore 23 of the plug 22 and when such pressure reaches a predetermined point, suflicient to overcome the spring pressure and the pressure within the interior of the tubing which latter pressure acts against the upper end of the plunger, thenthe plunger is moved to its uppermost position, with the annular shoulder .35 at the base of the pin 34 engaging the seat 28 within the cylinder (Figure 3). In this position, the bore 2'! at the upper end of the cylinder is closed and the gas inlet ports 31 are also closed, whereby gas cannot enter the tubing. At this time, the coiled spring 33 is under. tension and is exerting its force downwardly against the gas pressure acting against the lower end of the plunger. The upper end of the pin 34 is exposed to the pressure of the liquid in the interior of the tubing string through the port I8, chamber 11 and bore 2! and such pressure is urging the plunger downwardly. Therefore, it will be seen that the well liquid pressure plus the force of the compressed spring is urging the plunger toward a lowered position, which movement is resisted by the gas pressure in the casing acting against the lower end of the plunger.

As the liquid column in the well tubing l l continues building up to rise toward a normal standing liquid level, the pressure within the tubing acting against the upper end of the plunger is increased. When this pressure reaches a predetermined point, as determined by the size of the spring .33 and the gas pressure in the casing, the plunger is moved downwardly against the pressure of the gas, whereby the upper curved or tapered portion of the pin 34 is moved out of the bore 21 to open said bore and establish communication between the chamber 28 in the upper portion of the cylinder 21 and the interior of the tubing. At the same time that the upper portion of the pin moves out of the bore 21, the lower ends of the grooves or flutes 36 in the plunger move opposite the radial gas inlet ports 37 in the cylinder and when this occurs the lifti as from the casing flows upwardly through the channels into the chamber 28, then through the bore 21, port 18 and finally into the tubing II to aerate the liquid column.

As soon as the gas enters the tubing it starts the well liquid above the port l8 moving upwardly and such upward movement reduces the pres sure above the pin 34 and plunger. The lower end of the plunger is exposed to the gas pressure which is constant and, therefore, the reduction of the pressure above the plunger causes said plunger to again move upwardly. Such upward movement of the plunger moves the upper reduced end of thepin into the bore 27 and as said pin enters the opening the cross-sectional flow area of the bore is gradually reduced. This gradual reduction increases the velocity of the gas passing around the pin 34 through said bore and at the same time a greater cross-sectional pin area is moving into the bore. The increased velocity of the gas flowing through the bore further reduces the pressure above the pin and, also, the pin entering the bore acts with the same efiect as a piston within a cylinder, Whereby the rate of movement of the plunger is increased as it moves upwardly. The plunger continues its upwardmovement until the shoulder 35 engages the seat 29. 1 l

The contour or curvature of the pin is a controlling factor as to the rate or speed of upward movement of the plunger and this is one of the features of the invention. As shown in Figure 1, the curved taper is more or less gradualand covers approximately one-third of the length of the pin. ;Therefore, as the pin moves into the bore, the reduction of flow area around the pin is relatively gradual and the rate of increase in speed of movement of the plunger is gradual. If the'pinwere made with a longer taper, as disclosed in Figure 14, the reduction of flow area and the speed of movement of the pin would be decreased, with the result that it would require a longer time for the shoulder to engage the seat and, thus, more gas would enter the tubing upon each actuation of the plunger. Similarly, if the contour of the pin were more rounded, as shown inFigure 13, the reduction of flow area of the bore would be more abrupt; also, such contour would cause the cross-sectional area of the pin entering the bore 21 to be rapidly increased and thereby result in a more rapid upward movement of the plunger. Such movement would, of course, reduce the volume of gas admitted to the tubing uponeach actuation of the plunger. Thus, it will be apparent that by varying the contour of the pin, the time required for the plunger to complete its upward movement may be controlled, whereby the volume of gas in each charge admitted to the tubing may be accurately controlled.

,As the plunger 3|] moves upwardly, the lower ends of the grooves or channels 36 therein also move upwardly in the reduced portion 25 of the cylinder bore and, as has been explained, the

grooves are so disposed that the lower ends of said grooves move upwardly past the inlet ports 3'! as the shoulder on the plunger approaches its seat 29. As soon as the lower ends of said grooves pass the ports 31, the lifting gas from the casing is shut oif. However, since the shoulder 35 has not yet engaged the seat 29, the remaining gas in the chamber 28 may escape into the tubing to further lower thepressure above the; pin. The constant gas pressure below the plunger 3|! then moves the shoulder into engagement with the seat 29 and closes the bore. It'is noted that the shutting off of the'gas supply prior to the completion of movement of the plunger assures the plunger moving to a seated position. Also, thecoiled spring 33 is further compressed after the gas is cut ofi whereby it is placed under additional tension, with the result that a lighter spring may be employed and still obtain the necessary force for controlling the pressure differential required to open the valve.

After the plunger is seated to close thebore 21, (Figure 3) the parts remain in this position until the pressure of the well liquid within the tubing again builds up to th predetermined point necessary to unseat the plunger. The size and force of the spring aid in controlling the. pressure differential and said spring may be varied to take care of various well conditions. Obviously, the device operates to admit a charge of gas to raise the well liquid and after the charge is admitted, the device positively shuts 011 the gas until the same is again needed. This makes the valve particularly adapted for use as an intermitter but it is noted that it may be employed as an ordinar yVflow valve, in which event a plurality of the devices 'A would; be mounted in the tubing-string at spaced elevations therein.

In Figures 1 to- 4, the device has been illustrated as mounted on the outside of the tubing string being located at any desired elevation in the tubing string. It may be desirable, in some instances, to mount the cylinder 2|, wherein the valve plunger 3!! is located, on the lower end of the tubing I. In such case, an elongate tubular housing 4|! is connected to the extreme lower end of the well tubing II by means of a coupling collar 4|. The'lower end of the housing 4!] is closed. The couplingcollar 4| is formed'with diametrically opposed, radial ports 42 which have their inner ends communicating with an axial bore '43 provided in the lower end of the collar 4|. The extreme lowerend of the bore 43' is internally screw-threaded to receive the threaded upper end of the cylinder 2|, whereby said cylinder is supported axially within the housing 4|]. As is clearly shown in Figure 5, the outer diameter of the cylinder 2| 'is less than the inner diameter of theyhousing 46, whereby an annular space is-formed therebetween. Also, the lower end of the cylinder terminates short of the bottom of said housing. a

The ports 42'Which are located in the coupling collar 4| havetheir outer ends communicating with the interior of the well casing Ill. Vertical passages 44 extend through the coupling collar 4| on each side of the ports 42 and these passages establish a communication between the in terior of the well. tubing and the interior of the housing 40. With such arrangement, it will be evident that the pressure within the well tubing may pass downwardly into the interior of the housing and act against the underside of the plunger 3|], while the pressure within the casing mayact downwardly on the upper end of the plungeriand pin 34through the ports 42 and the bore 43. v

The operation of this device is substantially the same as the form shown in Figures 1 to 4, with the exception that the lifting gas is intro-' duced into the well tubing andflows downwardly into the housing 49 to act "against the bottom or lower end of the plunger 30. The well packer l2 shown in the first form is eliminated, whereby the well liquid may rise upwardly in the well casing Ill. When the valve plunger 30 is actuated, as has been described, the lifting gas from the interior of the housing may pass through the inlet ports 31 in the cylinder 2| and may then flow upwardly through the bore 43 and ports 42 into the well casing. Thislifting gas will aerate the well liquid standing'in said casing and will thereby raise the same to the surface of the well. Manifestly, the pressure of the lifting gas is actingagainst the lower end of the plunger, while the pressure of the well liquid in the casing I0 is acting against the upper end of said plunger, whereby the operation of the plunger is exactly the same as has been described.

In Figure 9, a slightly modified form of plunger 30 is shown. This plunger is constructed similarly to the plunger 30, with the exception that the channels or grooves 36' are extended substantially throughout the length of the plunger.

channels 36 and into the chamber 28, from where it may flow into the interior of the tubing, as described. When the plunger 30' moves upwardly to engage the shoulder 35 with the seat 29, the flow of gas into the tubing is cut off. However, as soon as the plunger is moved downwardly, the lifting gas may pass through the channels 36 and into the tubing. This form is substantially the same as the form shown in Figure 1, except that another means of introducing the gas into the chamber 28 is illustrated.

In Figures 11 and 12, still another form of the invention is shown. In this form, the lower end of the cylinder 2| is closed by a plug 45, which is substituted for the plug 22 in the other form.

This plug is formed with an axial bore 46 having radial ports 41 communicating with its lower end, whereby-the gas from the casing may enter the bore 45. The upper end of the plug 45 is conical to provide an inclined seating surface 48 and a plurality of inclined ports 49 extend from this seating surface downwardly to the upper end of the bore 46. Manifestly, gas from the casing which enters the bore 46 may pass upwardly through the inclined ports 49 and into the interior of the cylinder 2|.

A tubular plunger 55 is slidable within the reduced portion 25 of the cylinder bore and this plunger is formed with an external annular flange at its lower end. The underside of the flange is bevelled to provide a seating surface 52, which is complementary to the seating surface 48 of the plug 45. The flange is of such size as to close the inclined ports 49, when the plunger is in its lowermost position. A coiled spring 53 surrounds the lower end of the plunger and is confined between the flange 5| and the internal annular shoulder 26 formed within the bore of the cylinder. This spring exerts its pressure to constantly urge the plunger to its lowermost position and operates in the same manner as the spring 33 of the other form. The bore 50' of the plunger 50 terminates short of the upper end of said plunger and a plurality of inclined outlet ports 54 extend from the upper end of the bore to the outer surface of the plunger. The ports are so located that when the plunger is in its lowermost or seat-. ed position, said ports are within the reduced portion of the cylinder bore, whereby any gas that might be within the bore 55 cannot escape therefrom. The pin 34 is made integral with the upper end of the plunger 50.

The plunger 59 is operated in the same manner as the plungers and hereinbefore described and when the shoulder 35 formed at the base of the pin 34 is seated on the shoulder 29 within the cylinder bore, the gas from the casing enters the interior of the cylinder 2| and then passes upwardly through the bore 55 of the plunger. From the bore, the gas flows through the inclined ports 54 and into the chamber 28, but since the shoulder 35 is in a seated position, said gas cannot enter the interior of the well tubing I When the plunger 50 is moved downwardly to open the upper end of the bore 21 of the cylinder 2|, the gas may then enter the interior of the tubing since communication is established between the chamber 28 and said tubing. This flow may continue until the pressure above the plunger decreases to the point where the gas pressure acting against the lower end of the plunger may move said plunger to its seated position. Manifestly, this form of the invention produces all of the advantages and improved results as the other forms and operates in substantially the same manner.

In the forms disclosed, the valve element has been shown as operating with the pin 34 at its upper end but it is pointed out that the device would operate just as efficiently if it were reversed, with the pin 34 at its lower end. In such case, the well liquid pressure would be directed against the pin which would be the lower end of the device.

The foregoing description of the invention is explanatory thereof and various changes in the size, shape and materials, as well as in the details of the illustrated construction may be made, within the scope of the appended claims, without departing from the spirit of the invention.

What We claim and desire to secure by Letters Patent is:

1. A flow device including, a well tubing string having a well liquid inlet, a tubular body adapted to be connected in a well tubing string and having the upper end of its bore communicating with the well liquid column within the tubing string, said body having inlet ports in its wall for admitting a lifting fluid into the bore of the body whereby said fluid may flow upwardly through the bore and into the liquid column, and a valve element slidable within the bore of the body for controlling the flow of lifting fluid through the ports and also for controlling the flow of fluid from the bore to the liquid column, said element having its upper end exposed to the pressure of the well liquid with its lower end constantly exposed to the pressure of the lifting fluid, whereby the element is actuated by the differential in such pressures.

2. A flow device including, a well tubing string, a tubular body adapted to be connected in the well tubing string and having one end of its bore communicating with the well liquid column within said tubing, said body having inlet ports in its wall for admitting a lifting fluid into the bore of the body whereby said fluid may flow upwardly through the bore and into the liquid column, a valve seat within the bore of the body, a valve element slidable within the bore of the body adapted to co-act with the ports for controlling the flow of lifting fluid through the ports and also adapted to engage the seat for controlling the flow of fluid from the bore to the liquid column, said element having one end exposed to the pressure of the well liquid with its other end exposed to the pressure of the lifting fluid, whereby the element is actuated by the differential in such pressures, and resilient means engaging the valve element for urging said element in a direction against the lifting fluid pressure, whereby said means aids the well liquid pressure in moving said valve element against said lifting fluid pressure.

3. A flow device including, a well tubing string, a tubular body adapted to be connected in the well tubing string and having one end of its bore communicating with the well liquid column within said tubing, said body having inlet ports in its wall for admitting a lifting fluid into the bore of the body whereby said fluidmay flow upwardly through the bore and into the liquid column, a valve seat within the bore of the body, a valve element slidable within the bore of the body adapted to co-act with the ports for controlling the flow of lifting fluid through the portsand also adapted to engage the seat for controlling the flow of fluid from the bore to the liquid column, said element having one end its other end exposed to the pressure of the lifting fluid, wherebythe element is actuated by the differential in such pressures, and means on the valve elementfor controlling the volume of lifting fluid admitted to the liquid column upon each operation of said valve element.

4. A flow device including, a well tubing string having a well liquid inlet, a tubular body adapted to be connected in a well tubing string and having the upper end of its bore communicating with the well liquid column within the tubing string, said body having inlet ports in its wall for admitting a lifting fluid into the bore of the body whereby said fluid may flow upwardly through the bore and into the liquid .column, a valve element slidable within the bore of the body for controlling the flow of lifting fluid through the ports and also for controllingthe flow of fluid from the bore to the liquid column, saidlelement having its upper end exposed to the pressure of the well liquid with its lower end constantly exposed to. the pressure of the lifting fluid, whereby the element is actuated by'the differential in such pressures, resilient means engaging thevalve element for urging said element in a direction against the lifting fluid pressure, whereby said means aids the well liquid pressure in moving said valve element against said lifting .fluidpressure, and means on the valve element for, controlling the volume of lift ing fluid admitted to the liquid column upon each operation of said valve element. H i

5. A flow device including,,concentric fluid conductors, means for introducing a lifting fluid into one of said conductors and for admitting the well liquidto the other, whereby a liquid column is built up in the latter, a tubular body adapted to be connected in the inner fluid conductor'and havingthe upper end of its bore communicating with the well liquid column, said bodyhaving inlet ports in its wall for admitting Jalifting 'fluidinto the .bore of the body-whereby said fluid may flow upwardly through the bore and into the liquid column, and a valve element slidable within the bore of the body for controlling the flow of lifting fluid through the ports and also for controlling the flow of fluid from the bore to the liquid column, said element having'its upper end exposed to the pressure of the well liquid with its lower end exposed to the pressure of the lifting fluid, wherebythe element is actuated by the differential in such pressures, the ports being so located with relation to the element that saidports are closed to shut ofi the lifting fluid before the element completes its movement to completely close the bore of the body. a V V 1 6. A flow device including, concentric fluid conductors, means for admitting the well liquid to one of the conductors to build up a liquid column therein and for introducing a lifting fluid to the other conductor,- an elongate cylinder adapted to be connected in the inner conductor and having a bore and also having an outlet leading'from the upper end of said bore to the well liquidcolumn, the lower end of said bore having communication with a source of lifting gas supply, the cylinder having gas inlet ports intermediate its ends which conduct liftinggas to the'bore of said cylinder, and a valve element slidable within the bore of the cylinder for controlling the flow of gas through the ports and also: for controlling the flow of gas from the bore through the outlt to' the liquid column,

said element having its upper end exposed to the well liquid pressure with its-lowerfend exposed to the lifting gas pressure,- whereby it is actuated by a predetermined differential in such valve element slidable within the bore .of the cylinder for controlling the flow of gas through the ports and also for controlling theflow of gas from the bore through the outlet to the liquid column, said element having'its upper end exposed to the well liquid pressure with its lower end exposed to the liftinggas pressure, whereby it is actuated by a predetermined differential in such pressures, and means at the upper end of the valve element and movable with relation to the outlet for controlling the volume of lifting gas admitted to the well liquid upon each operation of the element. i r r V 8. A flow device including, a' well tubingstring 4 having an outlet leading from the upper end of u said bore to the well liquid column within the tubing string, the lower end of said bore having communication with a source'of lifting gas sup: ply, the cylinder having gas inlet ports inter-, mediate its ends which conduct lifting gas to the bore of said cylinder, a valve element slidable within the bore of the cylinder for controlling the flow of gas through the ports'and also for con-p trolling the flow of gas from the bore through the outlet to the liquid column, said element having its upper end exposed to the well liquid pressure with its lower end exposed to the lifting gas pressure, whereby it is actuated by a predetermined differential'insuch pressures, and a pin having its upper surface reduced located at the upper end of the valve element and movable with relation to the outlet for controlling the volume of gas admitted to the liquid column upon each operation of said valve element. 1

9. A' flow device including, a well tubing string having a well liquid inlet whereby a liquid column may rise therein, an elongate cylinder adapted to be connected in the tubing string and having a vertically'disposedbore and'also having an outlet leading from the upper end of said bore to the well liquid column within the.- tubing string, the lower end of said bore having communicationpwith a sourceof lifting gas sup ply, the cylinder having gas inlet ports intermediate its end which conduct lifting gas to the;

bore of said cylinder, and a valve element slidable within the bore of the cylinder for controlling the flow of gas from the bore through the outlet to the liquid column and also for being so located with relation to the element that said ports are closed to shut off the lifting fluid before the element completes its movement to completely close the bore of the body.

10. A flow device including, a well tubing string having a well liquid inlet whereby a liquid column may rise therein, an elongate cylinder adapted to be connected in the'tubing string and having a bore and also having an outlet leading from the upper end of said bore to the well liquid column within the tubing string, the lower end of said bore having communication with a source of lifting gas supply, the cylinder having gas inlet ports intermediate its ends which conduct lifting gas to the bore of said cylinder, and a valve plunger slidable in the bore of the cylinder and having channels in its outer surface which channels are arranged to register with the inlet ports to admit lifting gas to the bore of said cylinder, the plunger having its upper end movable relative to the outlet so as to also control the flow therethrough, said .plunger being actuated by a predetermined differential in pressure between the well liquid and the lifting gas.

11. A flow device including, a well tubing string having a well liquid inlet whereby a liquid column may rise in said tubing string, a tubular body adapted to be connected in the well tubing string and having the upper end of its bore communicating with the well liquid column, said body having inlet ports in its wall for admitting a lifting fluid into the bore of the body whereby said fluid may flow upwardly through the bore and into the liquid column, a valve element slidable within the bore of the body for controlling the flow of lifting fluid through the ports and also for controlling the flow of fluid from the bore to the liquid column, said element having its upper end exposed to the pressure of the well liquid with its lower end exposed to the pressure of the lifting fluid, whereby the element is actuated by the differential in such pressures, and means at the lower end of the valve element for preventing a back flow of well liquid from the tubing string when the lifting fluid pressure is below that of said well liquid.

12. A flow device including, concentric fluid conductors, means for admitting the well liquid to one of said conductors to build up a liquid column therein and for introducing a lifting gas to the other conductor, a tubular ,body adapted to be connected in the inner conductor and having the upper end of its bore communicating with the well liquid column, said body having inlet ports in its wall for admitting a lifting fluid into the bore of the body whereby said fluid may flow upwardly through the bore and into the liquid column, and a valve element slidable within the bore of the body for controlling the flow of lifting fluid through the ports and also for controlling the flow of fluid from the bore to the liquid column, said element having its upper end exposed to the pressure of the well liquid with its lower end constantly exposed to the pressure of the lifting fluid, whereby the element is actuated by the differential in such pressures.

13. A flow device including, concentric fluid conductors, means for admitting the well liquid to one of said conductors to build up a liquid column therein and for introducing a lifting gas to the other conductor, a tubular body adapted to be connected in the inner conductor and having the upper end of its bore communicating with the well liquid column, said body having inlet ports in its wall for admitting a lifting fluid into the bore of the body whereby said fluid may flow upwardly through the bore and into the liquid column, a valve element slidable within the bore of the body for controlling the flow of lifting fluid through the ports and also for controlling the flow of fluid from the bore to the liquid column, said element having its upper end exposed to the pressure of the well liquid with its lower end constantly exposed to the pressure of the lifting fluid, whereby the element is actuated by the differential in such pressures, resilient means engaging the valve element for urging said element in a direction against the lifting fluid pressure, whereby said means aids the well liquid pressure in moving said valve element against said lifting fluid pressure, and means on the valve element for controlling the volume of lifting fluid admitted to the liquid column upon each operation of said valve element.

14. A flow device including, a well tubing string having a well liquid inlet whereby a well liquid column may rise therein, a tubular body adapted to be connected in the tubing string and having the upper end of its bore communicating with the well liquid column, said body having inlet ports in its wall for admitting a lifting fluid into the bore of the body whereby said fluid may flow upwardly through the bore and into the liquid column, and a valve element slidable within the bore of the body for controlling the flow of lifting fluid through the ports and also for controlling the flow of fluid from the bore to the liquid column, said element having its upper end exposed to the pressure of the well liquid with its lower end exposed to the pressure of the lifting fluid, whereby the element is actuated by the differential in such pressures, the ports being so located with relation to the element that said ports are closed to shut off the lifting fluid before the element completes its movement to completely close the bore of the body.

15. A flow device including, a well tubing string, a well casing surrounding said tubing string and having a well liquid inlet whereby a liquid column may rise therein, means for introducing a lifting fluid into the tubing string, comprising a tubular body connected in the tubing string and having the upper end of its bore communicating with the well casing and the liquid column therein, the lower end of said bore having communication with the tubing string, said body having inlet ports in its wall for admitting a lifting fluid into the bore of the body whereby said fluid may flow upwardly through the bore and into the liquid column, and a valve element slidable within the bore of the body for controlling the flow of lifting fluid through the ports and also for controlling the flow of fluid from the bore to the liquid column, said element having its upper end exposed to the pressure of the well liquid with its lower end constantly exposed to the pressure of the lifting fluid, whereby the element is actuated by the differential in such pressures.

16. A flow device including, a well tubing, a tubular body adapted to be connected in the well tubing string and having the upper end of its bore communicating with the well liquid column within the tubing, means for admitting a lifting gas into the bore of the body, a single valve element slidable within the passage and having a longitudinal recess in its exterior coacting. with the last named means for controlling the admission of gas into the bore, the valve element also functioning to control the flow of gas from the bore into the; well liquid column in the tubing, said valve element having one end exposed to the well liquid pressure and'its opposite end exposed to the lifting gas pressure, whereby it is operated by the difierential in such pressures.

, 17. As a sub-combination in a well flowing apparatus, a flow device including a cylinder than the length of such portion, said plunger having channels in itssurface for :permitting a flow past the plunger, said channels coacting with the reduced portion of the bore to completely close flow past the plunger, the extremities of said channels being gradually reduced whereby as said channels move into the bore toward a completely closed position, the flow through said channels is gradually reduced and metered. 1 V r 18. A flow device including, a well tubing string having a well liquid inlet, a tubular body adapted to be connected in the well tubing string vand having one end of its bore reduced and communicating with the well liquid within the tubing string, an annular valve seat within the bore adjacent the reduced portion, the opposite end of the bore communicating with the area outside the tubing string through a reduced port, a second valve seat adjacent the port, said body having a lifting fluid inlet intermediate the ends of the body for admitting a lifting fluid into the bore of the body, a single valve plunger slidable in the bore of the body and having a sealing fit therein, said plunger being movable between the valve seats therein for controlling the flow of lifting fluid from the bore of the body into the well tubing, said plunger having its ends tapered to form seating surfaces for engaging the valve seats, and a coiled spring surrounding the plunger and urging said plunger to a position permitting a flow of lifting fluid into the well tubing string.

CHARLESVS. CRICIQ/IER. JOHNYJ. LANE. 

